An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

G. Lacedelli; L. Malavolta; L. Borsato; G. Piotto; D. Nardiello; A. Mortier; M. Stalport; A. Collier Cameron; E. Poretti; L. A. Buchhave; M. López-Morales; V. Nascimbeni; T. G. Wilson; S. Udry; D. W. Latham; A. S. Bonomo; M. Damasso; X. Dumusque; J. M. Jenkins; C. Lovis; K. Rice; D. Sasselov; J. N. Winn; G. Andreuzzi; R. Cosentino; D. Charbonneau; L. Di Fabrizio; A. F. Martnez Fiorenzano; A. Ghedina; A. Harutyunyan; F. Lienhard; G. Micela; E. Molinari; I. Pagano; F. Pepe; D. F. Phillips; M. Pinamonti; G. Ricker; G. Scandariato; A. Sozzetti; C. A. Watson

doi:10.1093/mnras/staa3728

An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

G. Lacedelli^*, L. Malavolta, L. Borsato, G. Piotto, D. Nardiello, A. Mortier, M. Stalport, A. Collier Cameron, E. Poretti, L. A. Buchhave, M. López-Morales, V. Nascimbeni, T. G. Wilson, S. Udry, D. W. Latham, A. S. Bonomo, M. Damasso, X. Dumusque, J. M. Jenkins, C. LovisK. Rice, D. Sasselov, J. N. Winn, G. Andreuzzi, R. Cosentino, D. Charbonneau, L. Di Fabrizio, A. F. Martnez Fiorenzano, A. Ghedina, A. Harutyunyan, F. Lienhard, G. Micela, E. Molinari, I. Pagano, F. Pepe, D. F. Phillips, M. Pinamonti, G. Ricker, G. Scandariato, A. Sozzetti, C. A. Watson

^*Corresponding author for this work

Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

15 Citations (Scopus)

Abstract

Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterization of the planetary system orbiting the late G dwarf TOI-561. After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period P_b = 0.45 d, mass M_b = 1.59 ± 0.36 M_⊕ and radius R_b = 1.42 ± 0.07 R_⊕, and three mini-Neptunes: TOI-561 c, with P_c= 10.78 d, M_c = 5.40 ± 0.98 M_⊕, R_c = 2.88 ± 0.09 R_⊕; TOI-561 d, with P_d = 25.6 d, M_d = 11.9 ± 1.3 M_⊕, R_d = 2.53 ± 0.13 R_⊕; and TOI-561 e, with P_e = 77.2 d, M_e = 16.0 ± 2.3 M_⊕, R_e = 2.67 ± 0.11 R_⊕. Having a density of 3.0 ± 0.8 g cm^-3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

Original language	English
Pages (from-to)	4148-4166
Number of pages	19
Journal	Monthly Notices of the Royal Astronomical Society
Volume	501
Issue number	3
Early online date	8 Dec 2020
DOIs	https://doi.org/10.1093/mnras/staa3728
Publication status	Published - Mar 2021

Bibliographical note

Publisher Copyright:
© 2021 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.

Keywords

planets and satellites: composition
planets and satellites: detection
stars: individual: TOI-561 (TIC 377064495, Gaia DR2 3850421005290172416)
techniques: photometric
techniques: radial velocities

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1093/mnras/staa3728

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Lacedelli, G., Malavolta, L., Borsato, L., Piotto, G., Nardiello, D., Mortier, A., Stalport, M., Collier Cameron, A., Poretti, E., Buchhave, L. A., López-Morales, M., Nascimbeni, V., Wilson, T. G., Udry, S., Latham, D. W., Bonomo, A. S., Damasso, M., Dumusque, X., Jenkins, J. M., ... Watson, C. A. (2021). An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561. Monthly Notices of the Royal Astronomical Society, 501(3), 4148-4166. https://doi.org/10.1093/mnras/staa3728

@article{13c706ebee3b48bba79948ae6a6b0a3e,

title = "An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561",

abstract = "Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterization of the planetary system orbiting the late G dwarf TOI-561. After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm-3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.",

keywords = "planets and satellites: composition, planets and satellites: detection, stars: individual: TOI-561 (TIC 377064495, Gaia DR2 3850421005290172416), techniques: photometric, techniques: radial velocities",

author = "G. Lacedelli and L. Malavolta and L. Borsato and G. Piotto and D. Nardiello and A. Mortier and M. Stalport and {Collier Cameron}, A. and E. Poretti and Buchhave, {L. A.} and M. L{\'o}pez-Morales and V. Nascimbeni and Wilson, {T. G.} and S. Udry and Latham, {D. W.} and Bonomo, {A. S.} and M. Damasso and X. Dumusque and Jenkins, {J. M.} and C. Lovis and K. Rice and D. Sasselov and Winn, {J. N.} and G. Andreuzzi and R. Cosentino and D. Charbonneau and {Di Fabrizio}, L. and {Martnez Fiorenzano}, {A. F.} and A. Ghedina and A. Harutyunyan and F. Lienhard and G. Micela and E. Molinari and I. Pagano and F. Pepe and Phillips, {D. F.} and M. Pinamonti and G. Ricker and G. Scandariato and A. Sozzetti and Watson, {C. A.}",

note = "Publisher Copyright: {\textcopyright} 2021 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.",

year = "2021",

month = mar,

doi = "10.1093/mnras/staa3728",

language = "English",

volume = "501",

pages = "4148--4166",

journal = "Monthly Notices of the Royal Astronomical Society",

issn = "0035-8711",

publisher = "SIPRI/Oxford University Press",

number = "3",

}

Lacedelli, G, Malavolta, L, Borsato, L, Piotto, G, Nardiello, D, Mortier, A, Stalport, M, Collier Cameron, A, Poretti, E, Buchhave, LA, López-Morales, M, Nascimbeni, V, Wilson, TG, Udry, S, Latham, DW, Bonomo, AS, Damasso, M, Dumusque, X, Jenkins, JM, Lovis, C, Rice, K, Sasselov, D, Winn, JN, Andreuzzi, G, Cosentino, R, Charbonneau, D, Di Fabrizio, L, Martnez Fiorenzano, AF, Ghedina, A, Harutyunyan, A, Lienhard, F, Micela, G, Molinari, E, Pagano, I, Pepe, F, Phillips, DF, Pinamonti, M, Ricker, G, Scandariato, G, Sozzetti, A & Watson, CA 2021, 'An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561', Monthly Notices of the Royal Astronomical Society, vol. 501, no. 3, pp. 4148-4166. https://doi.org/10.1093/mnras/staa3728

TY - JOUR

T1 - An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

AU - Lacedelli, G.

AU - Malavolta, L.

AU - Borsato, L.

AU - Piotto, G.

AU - Nardiello, D.

AU - Mortier, A.

AU - Stalport, M.

AU - Collier Cameron, A.

AU - Poretti, E.

AU - Buchhave, L. A.

AU - López-Morales, M.

AU - Nascimbeni, V.

AU - Wilson, T. G.

AU - Udry, S.

AU - Latham, D. W.

AU - Bonomo, A. S.

AU - Damasso, M.

AU - Dumusque, X.

AU - Jenkins, J. M.

AU - Lovis, C.

AU - Rice, K.

AU - Sasselov, D.

AU - Winn, J. N.

AU - Andreuzzi, G.

AU - Cosentino, R.

AU - Charbonneau, D.

AU - Di Fabrizio, L.

AU - Martnez Fiorenzano, A. F.

AU - Ghedina, A.

AU - Harutyunyan, A.

AU - Lienhard, F.

AU - Micela, G.

AU - Molinari, E.

AU - Pagano, I.

AU - Pepe, F.

AU - Phillips, D. F.

AU - Pinamonti, M.

AU - Ricker, G.

AU - Scandariato, G.

AU - Sozzetti, A.

AU - Watson, C. A.

PY - 2021/3

Y1 - 2021/3

N2 - Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterization of the planetary system orbiting the late G dwarf TOI-561. After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm-3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

AB - Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterization of the planetary system orbiting the late G dwarf TOI-561. After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm-3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

KW - planets and satellites: composition

KW - planets and satellites: detection

KW - stars: individual: TOI-561 (TIC 377064495, Gaia DR2 3850421005290172416)

KW - techniques: photometric

KW - techniques: radial velocities

UR - http://www.scopus.com/inward/record.url?scp=85100809245&partnerID=8YFLogxK

U2 - 10.1093/mnras/staa3728

DO - 10.1093/mnras/staa3728

M3 - Article

AN - SCOPUS:85100809245

SN - 0035-8711

VL - 501

SP - 4148

EP - 4166

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 3

ER -

An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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